Harman Kardon DPR2005 Service Manual page 49

PR1005/DPR2005
D
5.3
The GR70 does not maintain control register settings when power is off. After reset the GR70 amplifier is in a passive state, all
CONSUMER
registers are in their reset state, which results in the outputs being muted.
The following procedure activates the amplifier:
• SET MD0 and MD1
• To activate the output stages, SET the EAPD bit in the ConfF register 05H.
• The MPC bit in ConfA register 00H must be CLEARED for normal operation of the amplifier.
• Configure individual volume controls, mutes, and master volume registers as needed.
• MD0 and MD1 must remain SET for normal amplifier operation.
5.4
The PowerDown state is the condition where the supplies are at their nominal level, but the amplifier is inactive due to the assertion
or either /RESET or /PWRDWN. Chapters 13.3 through 13.5 describe PowerDown operation. To avoid output pops, the /RESET
input should not be used to transition from the active state to the PowerDown state.
PowerOff is the condition where one or more power supply is off. When transitioning from PowerOff to the condition where all
power supplies are at their nominal level, /RESET should be active. This insures that the amplifier initializes properly with no output
pops. When transitioning from active operation to PowerOff, put it in the PowerDown state or clear the EAPD bit in the ConfF
register 05H. From the PowerDown state (or EAPD low) the power supplies can be turned off without speaker output pops.
5.5
When enabling or disabling the second zone, the following procedure is used:
• SET MD1 and MD0.
• SET master mute bit, MMute, in Mmute register 06H.
• Power down the amplifier output stages, CLEAR EAPD bit in ComfF register 05H.
• CLEAR MD1 and SET Z2_EN.
• If the zone 2 input is analog, enable zone 2 analog input, SET Z2_AD_EN. The input format must also be configured for I
a 48kHz sample rate.
• Configure the digital input format and sample rate using ConfA register 00h and ConfB register 01H. Access to any other registers will
result in undesired operation. The Zone 2 outputs, CH5_OUT and CH6_OUT, are now assigned to input channels Five and Six.
• Program all parameters for zone 2 - EQ, volume, etc.
• SET MD1
• Restore the amplifier output stages: SET EAPD bit in ConfF register 05H and CLEAR the MMute bit in Mmute register 06H.
The amplifier is now ready for operation in the dual zone configuration.
5.6
The sample rate of the primary channels may be modified without disturbing the operation of Zone 2. This will be required when
switching between 44.1-48kHz, 96kHz, or 192kHz. Follow this procedure:
• Mute channels 1 through 4 and 7: SET bits C1M through C4M and C7M in Channel Mute register 08H.
• CLEAR MD0.
• Power down the primary amplifier output stages: CLEAR EAPD bit in ConfF register 05H.
• Configure the primary sample rate and digital input format using ConfA register 00h and ConfB register 01H. Access to any other
registers will result in undesired operation.
• SET MD0.
• Restore the amplifier output stages: SET EAPD bit in ConfF register 05H and CLEAR bits C1M through C4M, CM7 in Channel Mute
register 08H.
The amplifier is now ready for operation.
5.7
The amplifier digital outputs may be used to drive headphones via an external DAC. The speaker outputs of the primary output
channels can be muted for headphone only operation without disturbing the operation of Zone 2. The procedure is:
• CLEAR MD0.
• Power down the primary amplifier output stages, CLEAR EAPD bit in ConfF register 05H.
• SET MD0.
To restore the primary output channels:
• CLEAR MDO
• SET EAPD bit in ConfF register 05H.
ACTIVATING THE AMPLIFIER
POWER DOWN AND POWER OFF
ENABLING ZONE 2
SAMPLE RATE CHANGE WITH ZONE 2 ENABLED
HEADPHONE OPERATION WITH ZONE 2 ENABLED
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harman/kardon
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